LIVINGSTON, N.J. (WABC/CNN) - A New Jersey couple has filed a lawsuit seeking damages against a fertility clinic that they say helped them conceive a child but allegedly used the wrong sperm to do so.

The couple says years after their daughter’s birth, they discovered that only one of them, the mother, was the child’s biological parent.

"It wasn’t until the child was 2 years old that she started having - they’re both Caucasian - she started developing Asian features,” said David Mazie, the couple’s attorney.

The two are suing Institute for Reproductive Medicine and Science (IRMS) at St. Barnabas, a fertility clinic in Livingston, New Jersey, after an in vitro fertilization procedure in which they allege the wrong sperm was used.

"Negligence, recklessness, you call it what you want. This should never, ever happen,” Mazie said.

IRMS issued a statement.

“We are an organization comprised of passionate, dedicated medical professionals whose singular mission is to help our patients build their families," said IRMS representative Ronn Torossian.

"The integrity of our treatment processes are paramount and we are taking this matter very seriously. As such, we are thoroughly examining the alleged incident, which is said to have occurred in 2012. As patient privacy is core to what we do, we do not comment specifically on individual patient matters.”

The man, who believed he was the biological father of the girl, realized what had happened after a DNA test. According to court papers, the father told the mother “it said zero probability of father.” He informed the child’s mother in court, which led to confusion, as she didn’t know he wasn’t the biological father.

The girl is now 6 years old, and her parents want to know who her biological father is. She has a blood disorder that her non-biological father and mother don’t carry.

"They have a right to know who he is. They have a right to know his genetic history,” Mazie said.

While the couple has divorced, the non-biological father of the girl spends quality time with his daughter and has visitation rights.

"In his mind, this is his daughter. I mean, there’s a lot of emotional distress here,” Mazie said.

The couple has decided not to tell the girl about the issue at this time because “they don’t think she could fully understand.”

The in vitro procedure took place in November 2012.

"The court has now ordered that the clinic produce to us everybody of Asian decent who donated sperm, was inseminated during the critical times that family was there," Mazie said. "We want to find out who the genetic father is."

The institute is not commenting on the case because it’s in litigation.